Safety device for chairs



June 19, 1951 J. R. c. QUILTER 2,557,313

SAFETY DEVICE FOR CHAIRS Filed Jan. 6, 1947 F s sheets-sheet 1 INVENTORJune 19, 1951 J. R. c. QUILTER SAFETY DEVICE FOR CHAIRS 3 Sheets-Sheet 2Filed Jan. 6, 1947 "3 b vw mm R HQ @MN mm R wn m N W mm m mn SW 3 Q w w8 mm m. i, ,nng WM \m 4 9 mm mm. \m H mm W RN mm w mk g mm mm. W

June 19, 1951 J. R. c. QUILTER 2,557,313

SAFETY DEVICE FOR CHAIRS File'd Jan. 6, 1947 3 Sheets-Sheet 5 IuvsavroRJ0 H4N R. CQUILTER By My u/azaa ATTORNEYS Patented June 19, 1951 UNITED.TATES PATENT OFFICE SAFETY DEVICE FOR CHAIRS John Raymond CuthbertQuilter,

' wfiki llg, England Application January 6, 1947, Serial No. 720,451

. In Great Britain January 8, 1943 6 claims. (cl. 155-189) Thisinvention relates to safety or retaining devices for seats on aircraftandpth r vehicles such as racing motor cars, in which it is "customaryto provide safety straps "or harness for retaining the pilot or otheroccupant in his seat in spite of shocks, collisions or the like.

The invention has for its mainobject the provision of an improved safetydevice of this character, which allows definite freedom of 7 movementwithout any material restriction by the safety straps or harness, sothat the pilot'of an aircraft for example can move about 'on his seat orto a limited extent within'the cockpit, but in' the event of a suddenshock the safety device will operate to retain hiin in his seat by.holding the safety straps or harness tight until the efi'ects of theshock are at least partially removed; The

invention is particularly applicable te aircraft seats of the automatic:ejection type but may also be applied to normal seats of aircraft orother vehicles. 7

A further object of the invention is to provide one or more inertialocks which will allow the harness to yield to the Voluntary movementsof the pilot or other occupant in relation to his seat, but will holdthe harness tightly against sudden pulls due to shocks or the like.Automatic means may be provided forfreein'g the harness within apredetermined period after a shock which has been sufficiently severeto'bring the inertia look into operation; thus, the pilot willregainyhi's freedom of movementafter the shockhas passed; or again, inthe case of an automatic 'eje'ction'seat' on an aircraft, the shockcausedby the ejection of the pilot with his seat will lock the safetyharness so as to maintain him upon the seat but after a'suitable delayhe will be freed automati- 09,113; from the seat so that he may bringhis parachute into operation.

Another object is to provide'means for freeing the safety straps orharness manually at any time; these manual controlling-"means may bearranged to have one or more additionalyopera tive positions whereby theharness may be locked definitely and irrespective of shocks for examplebefore entering into aerobatics or violent move"- ments of the aircraft.

:Other objects and advantages of thelinvention will appear from thefollowing description, given with reference to the-accompanyingdiagrammatic drawings, in which: I}

Fig. l is a side view of an aircraft pilots seat.

Fig. 2 is a rear view of the seat. I

Figs. 2a and 2b are"view's in axial section on a larger scale of twodetails seen in Fig; 2 I

Fig. 3 shows the four positions of the manual control lever. V

Fig. 4 is 'a sectional view of an inertia locking device, as seen on theline 4-4 of Fig. 5;

Fig. 5 is an end view partly in section on the line 5-5 of Fig 4,showing the rocker and connected parts of the inertia locking device.

. Fig. 6 is a plan of Fig. 5, parts of the locking. device and itshousing being broken away.

Figs. '7 to 10 are end views of the rocker and connected parts of theinertia locking device in the four positions corresponding to the fourpositions of the control lever marked in Fig. 3.

In the embodiment of the invention illustrated in Figs. 1 and Z, asapplied to an aircraft seat, the safety harness includes two straps [0which passvover the occupants shoulders and through guide slots l I inthe back of the seat, where they are wound upon drums I2 mounted inhousings l3 below the slots, each drum receiving one of the strapstangentially and in a substantially horizontal direction. The straps aredetachably engaged with the drums, for example by inserting their freeends l0 into longitudinal slots [2" in the hubs of the drums, the strapsbeing then wound upon the hubs until they are drawn tight, thesuperposed coils holding the inner ends in the engaged position, as seenin Fig. 4.

Upon the shaft of each drum, inside the housing l3, there is fitted aninertia locking device 54, the operation of this device being such thatwhile tending to wind in the respective strap IU under a spring tensionof about three pounds for example, and allowing the strap to pay outslowly against that tension, it will hold the strap tightly if the speedof outward movement exceeds a certain rate. Thus, if the pilot leansforward in his seat, the straps ill of the safety harness will yield tothis movement, and when he leans back the inertia locking devices l4will wind in the two straps so as to take up the slack, but if a suddenshock tends to throw the pilot out of his seat,

I the movement will be resisted by a strong braking action or a positivelock which will prevent the safety straps from yielding.

The inertia device, as illustrated in Figs. 4 to 6, may comprise arocker 38 mounted freely upon the drum shaft and provided with one ormore moment arms 3! carrying lead weights 32, so that under theinfluence of forward or upward acceleration the rocker 3i} turns aboutthe shaft, thus forcing a bolt 33, brake shoe or the like into internalengagement with the rim of a wheel 34 secured to the drum on which thestrap H) is wound. This wheel is shown fitted inside a cylindricalextension of one of the end flanges 35 of I the drum which houses aclock spring 36 having member 42 providing a ball-race support at 4'3for the freely mounted rocker 30. This second coupling member iscontrolled by a rod l5 running substantially vertically behind the seatand jointed at its upper end to a bar l5a slidable diametrically throughthe housing l3; the bar l5a is formed with a keyhole slot 44 engagingthe second coupling member 42, whereby the latter. may be heldstationary by the narrow portion 4'5 of the slot making contact with twoopposite flats, 45 upon the coupling member, or allowed to revolvefreely by bringing the enlarged circular portion 4'! of the slot intoregister with the coupling member.

The control bar l5a is preferably formed with a widened portion 48around the keyhole slot, one wing 49 of this widened portion having arectangular aperture 50 engaging with a crank pin 5| upon the rocker 30,so that the longitudinal movement of the control rod and bar may also beemployed to force the rocker to turn in either direction for producingor for releasing the braking or locking action. The opposite wing 52 ofthe widened portion of the bar may have a series of notches 53, engagedby a spring latch 54 or the like, for locating it in the respectivepositions to control the inertia lock device.

The operation of the bolt 33 by movement of the rocker 30 is effectedthrough a pin 55 mounted in the forked rear end of the bolt, the pinbeing engaged by a slot 56 in an arm 51 extending from the body of therocker; in the normal position, as shown in Fig. 5, the rocker arm 51holds the bolt inward of its guide-tube 33a, the front end of the boltbeing thus clear of the wheel 34. On the other hand, movement of therocker in the anti-clockwise direction (as viewed in Fig. 5) will forcethe bolt 33 to the right, thus bringing its front end outwards intoengagement with the wheel 34, the interior of which is provided withrack teeth 34a; these teeth are preferably undercut on one face, asshown, and the front end of the bolt is also provided with an undercuttooth so as to take a positive hold of the wheel when engagement occurs.The spacing of the teeth 34a is such as to allow room for the entranceof the 4 of a shaft l1 extending transversely of the seat and near thebase thereof, each of the control rods l5 engaging with a crank arm l8secured to the shaft,

The hand lever l6, which may be duplicated by a similar lever at theother end of the shaft ll, can occupy any one of four positionscorresponding to the several positions of the control bars l5a; in thenormal position, with the lever l6 horizontal on the line I (Fig. 3),the inertia lock device has its second coupling sleeve held by thenarrow portion 45 of the keyhole slot in the control bar, as showninFig. 7, and the inertia lock will operate to resist sudden movements ofthe strap llldue to shocks. In the fully raised portion of the lever onthe line II (Fig. 3) the control bar will bring the enlarged circularportion 41 of its slot into register with the coupling sleeve; theinertia lock 'willthus be freed, as shown in Fig. 8, andthe harness canbe released at will. By forcing the lever l6 down below the horizontalto the line 111 (Fig. 3), the pilot can cause the control bar to operatethe crank pin 5| of the rocker in the inertia lock devices, therebyforcing the bolt 33 or the like into engagement with the wheel, as shownin Fig. 9; the strap ID will thus be locked against movement,irrespective of speed,

bolt-end between two adjacent teeth when the 7 bolt is forced out by therocker arm 51.

The rocker 35 is biased by a curved link or bail 58 pivoted upon a pin59 on one side of the rocker, the bail extending over the hub of therocker and being connected to one end of a coiled tension spring 60, theother end of which is anchored upon a post 6| screwed into an end-plate82 secured in the housing [3. The pull exerted upon the pin 59 by thespring 60 tends to maintain the rocker 30 in its normal position, untila sudden shock causes the weights 32 under the influence of theirinertia to turn the rocker upon its bearing 43 on the outside of thecoupling member 42, the turning movement taking place in theanticlockwise direction (as viewed in Fig. 5) as soon as this happens,the pull of the spring 60 is transferred to the opposite side of therocker axis, so as to make the slotted arm 51 thrust the bolt 33outwards into engagement with the wheel 34, with the result of lockingthe wheel and holding the strap l0 tight, as hereinbefore described.

A return movement of the rocker in the clockwise direction (as viewed inFig. 5), produced by action of the control rod and bar upon the crankpin 5|, will restore the pull of the spring 60 to the original side ofthe rocker axis, thus again as may be desirable in certain conditions.Lastly, by raising the lever to the position IV (Fig. 3), above thehorizontal but short of the fully raised position II, the control barcan be made to turn the rocker 30 back to the normal position, as shownin Fig. 10, thus preparing the device for normal operation as soon asthe lever is returned to the horizontal on the line I.

The harness may also include a pair of legstraps I9, which are fastenedat one end to the respective sides of the seat and can be passed beneaththe thighs to bring the other ends over into engagement with hinged pegsor levers 20 carried by another pair of cranks 2| upon the shaft II;these pegs 20 pass through eyes or loops 22 at the ends of theleg-straps and their extremities fit into housings 23 on the sides ofthe seat frame. The release of the harness by turning the shaft I! willwithdraw the pegs 20 from their housings and allow them to pivot so asto slip out of the eyes or loops 22, thereby freeing the leg-straps. Atthe same time, the shaft I! will pull down the control rods I5 connectedto the inertia locks, which will allow the free rotation of the twostrap-drums.

In the case of an automatic ejection seat on an aircraft, means may alsobe provided for an automatic release of the safety harness by anemergency actuator consisting for example of a piston connected toanother crank 24 upon the control shaft I1, the piston being enclosed ina cylinder 25 secured to the back of the seat, as shown in Fig. 2.. Thiscylinder, asshown in Fig. 2a, contains a small charge of explosive 21,which can be fired within the cylinder in order to drive down the piston28 for turning the control shaft by means of the crank 24, the chargebeing ignited electrically by an inertia switch 26. As shown in Fig. 2b,this switch includes a slidable piston 29 into which there is rigidlyfixed a dry cell 30 adapted to complete and energize an electricalcircuit through an igniter 3| for setting off a fuze 32; this piston isnormally held up by a buffer spring 33, which yields to the inertia ofthe piston when the seat is ejected. The fuze 32 is set with asufllcient delay action 76 to allow the pilot and seat to get clear ofthe aircraft before the explosive 21 is detonated and the release of thesafety harness takes place.

The safety harness straps it, which may be secured to a waist belt orother suitable part of the parachute harness, will be passed through theguide slots ll over the shoulders of the pilot or other occupant, afterhe has taken his seat with the leg straps ill drawn loosely up betweenhis thighs; the upper straps iii will then be engaged with their drumsand the latter rotated to wind up the straps to the desired tightness.The leg straps is will next be laid out over the thighs and their freeends engaged with the pegs or hitch levers 2%) on the control shaft ll,the latter being then turned forward into the horizontal position tobring the extremities of the pegs 20 into their housing 23. At the sametime,

the turning of the shaft ll lifts the vertical control rods E5 to bringthe rockers to their normal position. 5:

By the expressions strap and drum, as employed in the appended claims,there are to be understood any equivalent members, such as ropes, wiresor other tensile connections, and wheels, pulleys or the like,respectively.

What I claim is;

1. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being wound upon said drum,spring means for turning said drum in a direction to wind up said strap,a stationary housing for said drum, a bolt slidable within said housingfor movement into and out of locking engagement with said drum, a rockermounted in said housing and controlling the movement of said bolt, saidrocker being made operative to move said bolt in the direction ofengagement with said drum by inertia force in the event of a suddenmovement of said seat, and manually operable means for reversing saidrocker to free said drum from said bolt.

2. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being wound upon said drum,spring means for turning said drum in a direction to wind up said strap,a stationary housing for said drum, a bolt slidable within said housingfor movement into and out of locking engagement with said drum, aspring-biased rocker mounted in said housing and controlling themovement of said bolt, said rocker being made operative by itsspring-bias upon displacement by inertia force in the event of a suddenmovement of said seat, and means for reversing said spring-biased rockerto free said drum from said bolt, the spring-bias of said rocker thenholding said bolt clear of said drum.

3. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being wound upon said drum,spring means for turning said drum in a direction to wind up said strap,means for holding said drum against rotation, said holding means beingmade operative by inertia force in the event of a sudden movement ofsaid seat, a control shaft mounted transversely behind said seat, a handlever for turning said control shaft, a crank secured upon said controlshaft, and a connection from said crank to said holding means, theactuation of said control shaft by said hand lever being adapted to freesaid drum from said holding means.

4. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being wound upon said drum,spring means for turning said drum in a direction to wind up said strap,means for holding said drum against rotation, said holding means beingmade operative by inertia force in the event of a sudden movement ofsaid seat, a control shaft mounted transversely behind said seat, a handlever for turning said control shaf a crank secured upon said controlshaft, and a connection from said crank to said holding means, selectivesetting of said control shaft by said hand lever being adapted to placesaid drum under inertia-force control by said holding means or to freesaid drum from said holding means.

5. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being Wound upon said drum,spring means for turning said drum in a direction to wind up said strap,means for holding said drum against rotation, said holding means beingmade operative by inertia force in the event of a sudden movement ofsaid seat, a control shaft mounted transversely behind said seat, a handlever for turning said control shaft, a crank secured upon said controlshaft, and a connection from said crank to said holding means, selectivesetting of said control shaft by said hand lever being adapted to placesaid drum under inertia-force control by said holding means, to freesaid drum from said holding means or to render said holding meansoperative irrespective of any sudden movement of said seat.

6. A safety device comprising means for retaining the occupant of a seatthereon, said retaining means including a strap extending to the rear ofsaid seat, a rotatable drum, said strap being wound upon said drum,spring means for turning said drum in a direction to wind up said strap,means for holding said drum against rotation, said holding means beingmade operative by inertia force in the event of a sudden movement ofsaid seat, a pair of leg straps each fastened at one end to said seat, acontrol shaft mounted transversely behind said seat, a hand lever forturning said control shaft, cranks secured upon said control shaft, aconnection from one of said cranks to said holding means, and lockingmembers carried by two others of said cranks for engaging the other endsof said leg straps, the actuation of said control shaft by said handlever being adapted to free said drum from said holding means and torelease said locking members from said leg straps.

JOHN RAYMOND CUTHIBERT QUILTER.

REFERENCES CITED The following references are of record in'the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,270,636 McDaniel June 25, 19181,948,158 Barr Feb. 20, 1934 2,195,334 Lethern Mar. 26, 1940 2,292,386Manson Aug. 11, 1942 2,394,523 Pancoe Feb. 5, 1946 2,403,653 GeoheganJuly 9, 1946

